Presentation Outlines Long-term CV Risks of Gestational Diabetes

In a symposium hosted by the journal Circulation at the 5th annual Heart in Diabetes conference, Erica Gunderson, PhD, MS, MPH, a professor of Health Systems Science at the Kaiser Permanente Bernard J. Tyson School of Medicine and senior research scientist at Kaiser Permanente Northern California Division of Research, highlighted the long-term risks that women who develop gestational diabetes (GD) face, even after achieving normoglycemia.

Notably, presented findings showed that even women who achieved sustained normoglycemia after GD had a 2 times higher risk of atherosclerotic cardiovascular disease (ASCVD) in midlife.

Gunderson’s research evaluated glucose tolerance, GD incidence, and subsequent development of coronary artery calcium (CAC) over time. Describing this group of patients as “extremely vulnerable to heart disease,” Gunderson presented an analysis of data from the Coronary Artery Risk Development in Young Adults (CARDIA) study. Specifically, Gunderson and colleagues looked at the life course of child-bearing women starting at reproductive ages and continuing several decades post pregnancy.

GD is one of the most common adverse events during pregnancy, affecting 10% to 12% of all US pregnant women, and is associated with subsequent adverse cardiovascular outcomes. This evidence poses a “unique, I would say, potentially neglected opportunity for cardiovascular disease prevention in women,” Gunderson said.

Among those who develop GD, approximately 35% will develop prediabetes after pregnancy, while between 40% and 50% of women with GD are classified as obese prior to pregnancy. In addition, GD “is associated with a 7-fold higher risk of developing type 2 diabetes (T2D) and about 20% to 50% of women with GD will develop T2D within a fairly short period of time, 5 to 10 years after delivery,” she explained.

Gunderson and colleagues sought to evaluate levels of glucose tolerance across women’s reproductive years following pregnancy and determine its relationship to GD incidence and risk of ASCVD. ASCVD risk was measured via CAC levels, which have been shown to be a strong predictor of ASCVD in young adults.

Women participants were followed from 1985 to 2016 and were between ages 18 and 30 years at baseline. A total of 1133 women without diabetes at baseline had at least 1 singleton birth (n = 2066) over the course of the study window. The CARDIA study cohort is comprised of 50% Black and 50% White adults.

Researchers found:

• Of 1133 women, 139 (12.3%) reported GD and had a mean (SD) age of 47.6 (4.8) years at follow-up.
• CAC was present in 25% (34 of 139) of women with GD and 15% (149 of 994) of women with no GD.
• In comparison with no GD/normoglycemia, adjusted HRs were 1.54 (95% CI, 1.06-2.24) for no GD/prediabetes, 2.17 (95% CI, 1.30-3.62) for no GD/incident diabetes, and 2.34 (95% CI, 1.34-4.09), 2.13 (95% CI, 1.09-4.17), and 2.02 (95% CI, 0.98-4.19) for GD/normoglycemia, GD/prediabetes, and GD/incident diabetes, respectively (overall P = .003).

“In summary, [in] women without previous GD, the graded increase in risk of CAC was associated with worsening glucose tolerance. Women with GD had a 2-fold higher risk of CAC across all levels. Midlife ASCVD risk among women with a history of GD may not be diminished by attaining normoglycemia,” Gunderson said.

These findings represent a paradigm shift as they underscore the continued risk that normoglycemic patients with previous incidence of GD face during their mid-life. They also highlight the importance of not waiting until women develop overt diabetes to start evaluating risk, Gunderson said.

“GD may entail underlying vascular changes and/or adversely affect development of ASCVD,” she continued, adding that “screening among women with a history of GD is needed to better risk stratify women for early ASCVD prevention.”

Currently, a gap in the literature exists when it comes to risk prediction models for CVD, as most never include patients who develop GD without T2D.

In response to a question raised on screening implementation from a systems perspective, Gunderson stressed the importance of studying this postpartum group.

“I think we need risk prediction models for diabetes and CVD. It's very hard to integrate the data from women because GD systematic screening didn't happen until the mid-late 1980s. So these older women who develop CVD events, they weren't screened for GD, so none of those risk prediction models could happen,” she said. “But we're entering a generation where we can get these outcomes…For these types of studies we really have to do more prospective, longer-term life course epidemiology.”